The field of data storage includes both volatile memory and non-volatile memory. Volatile memory loses stored information when power is removed from the volatile memory circuit. Non-volatile memory retains stored information even after power is removed. Some non-volatile memory designs permit reprogramming while other designs only permit one-time programming.
One time programmable (OTP) memory represents a type of non-volatile memory that may be programmed only once, typically, by opening a fuse to create a high impedance connection or by permanently closing an anti-fuse to create a low-impedance connection. An anti-fuse can be programmed by applying a high voltage to rupture the anti-fuse and create the low impedance connection.
OTP memory cells utilizing an anti-fuse may exhibit an unpredictable and wide range of IV (current-voltage) characteristics following programing because the anti-fuse rupture site location may vary from device to device. Consequently, there is a need for an OTP memory cell that exhibits improved predictability and improved IV characteristics.
The embodiments of the present disclosure will be described with reference to the accompanying drawings. The drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.